Secnidazole for Trichomoniasis: What the Placebo Trial Showed

A one-dose prescription can sound easier to fit into your week. If secnidazole comes up after a trichomoniasis diagnosis, ask why your clinician favors it for you and what the result will be checked against.

What the trial measured

The placebo trial randomized 147 women aged 15–65; primary analysis included 131 with positive trichomonas cultures and negative gonorrhea/chlamydia tests. Pregnant and breastfeeding women were excluded.¹

After secnidazole 2 g once orally, 59/64 had negative cultures at 6–12 days, versus 1/67 on placebo. Missing tests counted as positive.¹

An early negative culture does not establish symptom clearance or protection against reinfection.

At that visit, participants received the opposite treatment, including secnidazole for the placebo group. There was no long-term placebo comparison.¹ Ask your clinic how it will assess symptoms that persist after treatment.

What the result cannot compare

The trial did not compare seven-day metronidazole. Lupin sponsored it, and three authors were company employees.¹

The CDC’s² posted guideline recommends metronidazole 500 mg twice daily for seven days for women.² This placebo comparison cannot establish equality or superiority to that regimen.

Ask about the reason for the proposed prescription, previous treatment, side effects and whether you can complete the schedule. If another medicine has caused a reaction, give its name and describe what happened rather than simply saying antibiotics do not agree with you.

What current Solosec instructions require

Current US labeling permits Solosec for trichomoniasis from age 12, as a single oral 2 g packet. Sprinkle the whole packet onto applesauce, yogurt or pudding; consume within 30 minutes without chewing. Do not dissolve it in liquid.³

Avoid alcoholic drinks and preparations containing ethanol or propylene glycol during treatment and for at least two days afterward.³ Use the current instructions when reviewing older descriptions of this medicine.

Tell the prescriber about pregnancy or breastfeeding. Pregnancy data are insufficient to establish risk; breastfeeding is not recommended during treatment and for 96 hours afterward. Nitroimidazole allergy and Cockayne syndrome are contraindications. Vaginal yeast infection can occur.³

Have the pharmacist check your medicine list and demonstrate preparation before you take the packet. Ask what to do if you cannot finish it or develop new symptoms.

What still needs arranging

CDC² advises partner treatment and avoiding sex until everyone has completed treatment and symptoms have resolved. Sexually active women should be retested around three months later.²

The trial’s early culture visit is not a timetable for an early molecular test. For persistent or recurrent infection, CDC² advises waiting at least three weeks after treatment before a NAAT, because residual genetic material can affect results.² Contact the clinic about symptoms; let it select the test and timing.

Our trichomoniasis follow-up guide covers partner care and other STI testing questions.

Down There, Decoded includes “When the Smell Points Somewhere Else,” explaining why changed discharge can require testing for several possible causes. Use that section when organizing what to tell your clinician. See the book.